So I am trying to get my first drone up and running. A Eachine 250 racer.I have a Turnigy 9XR Pro transmitter with Frsky DJT ACCST module and a Frsky D4R-II 4CH Receiver.

I want to run the system on cppm but while in LibrePilot the transmitter never gets recognized. Through some tinkering I have learned that it just wasn't liking being in cppm, it only wants to work in pwm.

Should I invest in the frsky USB hub so I can update the firmware or is there just a setting I'm missing?